California is home to a large and diverse population of over 37 million individuals, including the largest Latino, Native American, Pacific Islander, and Asian populations in the U.S. A large percentage of these individuals are linguistically isolated. Disparities in care are well documented to be significantly higher among racial/ethnic minorities and among those with language barriers. Although California requires race, ethnicity, and language reporting, a lack of specific guidelines for what, how, and when this data should be collected has contributed to inconsistency in reporting, a significant barrier to better understanding the magnitude of health disparities. California's Office of Statewide Health Planning and Development (OSHPD), a state agency, is responsible for the routine collection of patient-level hospital inpatient, emergency department, and ambulatory surgery data across the state. The Patient Discharge Database has over 4 million discharges annually and is the largest single constituent database contributing to the AHRQ National Inpatient Sample and the largest inpatient database offered by AHRQ Healthcare Cost and Utilization Project. Over ten million emergency department encounters and 2.4 million ambulatory surgeries are reported to OSHPD annually. In response to RFA-HS-10-010, "ARRA OS: Recovery Act 2009 Limited Competition: Enhanced State Data for Analysis and Tracking of Comparative Effectiveness Impact: Improved Clinical Content and Race-Ethnicity Data (R01)," a team of allied researchers led by investigators from the University of California in collaboration with the leadership of the California Office of Statewide Health Planning and Development, propose a three- year programmatic intervention to improve the reliability, validity, and completeness of self-reported race, ethnicity, and primary language provided by hospitals in the three databases that are currently within OSHPD's regulatory mandate. The aims of the proposed project are to: 1. Perform a baseline assessment of race, ethnicity, and language data collection, reporting, and accuracy in hospitals in California and comparison states. 2. Directly improve the accuracy and reliability of race, ethnicity, and language information collected by hospitals (direct improvement to self-reported data). 3. Use supplemental data and statistical approaches to improve race and ethnicity measures reported by hospitals (indirect improvement to self-reported data). Through this AHRQ-funded project, we expect to make substantial and sustainable improvements to the reporting of race, ethnicity, and primary language among patients receiving care in California's hospitals. PUBLIC HEALTH RELEVANCE: The aim of the proposed research is to incrementally improve the completeness and accuracy of self-report race, ethnicity, and language collected from all patients treated as inpatients, emergency department patients, or receiving ambulatory surgery in California hospitals. Results can be used to more accurately identify and address potential health and healthcare disparities arising through issues related to race, ethnicity, and language.